Various universal hand splints have been used in the art to stabilize a wrist of a user in a neutral or slight dorsiflexion. Such hand splints are easily applied and removed. However, one of the major problems with hand and wrist injuries is a development of metacarpal-phalangeal joint extension deformities. These various prior art hand splints have not satisfactorily eliminated this problem.
A unitary device for immobilizing the thumb, hand and wrist of a user is disclosed in (Shen) U.S. Pat. No. 4,382,439. The disclosed device includes a shell formed of an integral piece of semi-rigid material having portions shaped to receive the upper forearm, hand, and thumb. This shell is substantially C-shaped with a longitudinal opening along the upper or dorsal side of the device. The wrist dorsiflexion angle is disclosed as being between 10.degree. and 40.degree., and preferably 30.degree.. A thumb opening is provided on the side of the device through which the top of the thumb extends while the fingers extend almost fully out of the device.
The use of opposed dorsal and palm arch splints to immobilize a forearm, wrist, and hand therebetween has been disclosed in prior art. For example, in (Kearns) U.S. Pat. No. 568,951, the opposed splints are designed to achieve a wrist dorsiflexion angle of 80.degree. to 75.degree. and a radial deviation angle of approximately 18.degree.. A similar device is disclosed in (Kearn) U.S. Pat. No. 315,512 in which the dorsiflexion angle is much smaller. It should be noted that the splints in the both of these patents result in the immobilization of the fingers of the user, although the thumb is evidently not immobilized.
In (Hansard) U.S. Pat. No. 1,469,315, a wrist support device including opposed splints is disclosed in which the splints terminate before the metacarpal-phalangeal joints. This allows full movement of the fingers of the user and additionally allows a sidewards movement of the wrist so that the device can be used as a wrist support for such sports as golf or billiards in which a back and forth movement of the wrist is a defective action.
In (Barbara) U.S. Pat. No. 3,938,509, there is disclosed a lightweight, manually formable splint constructed of an underlying framework of aluminum wire connecting a palm piece, a central holding piece, and a proximal holding piece. The palm support includes a thumb rest and the device is held on the arm of the user by velco straps. The central holding piece is adjustable along the wires and can be anchored in place by means of a tightening screw.